For lots of groove check out Soreption, Psycroptic, or Decapitated(especially Wind Of Creation)

For ridiculous speed and over-the-top stuff check out Archspire, Origin

For neoclassical stuff check out Spawn Of Possession and Necrophagist

For beautifully written and progressive stuff check out Beyond Creation, Death, Augury, The Faceless(especially Planetary Duality, the album before was more deathcore and the one after was more prog death with lots of clean sections and all. still both are great))